* PVR-350 all functions work, but TV-Out isn't well suited for Myth, since it isn't accelerated and the MPEG decoder isn't well supported any longer.

* PVR-350 all functions work, but TV-Out isn't well suited for Myth, since it isn't accelerated and the MPEG decoder isn't well supported any longer.

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* Hauppauge WinTV-HVR 1600. Includes both an ATSC high-def tuner and an analog cable TV tuner, but is apparently not yet supported by the [[IVTV]] drivers. There is a beta driver in development. http://linuxtv.org/hg/~hverkuil/cx18/. Analog NTSC has partial support.

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== Caveats ==

== Caveats ==

Revision as of 01:30, 28 November 2009

Video capture cards are used to get the picture from the cable, aerial, or satellite television source into the PC.

They decode and capture the video signal from the channel you want to view or record. Most cards include a tuner to capture an specific TV signal (called 'tuner cards'). Video capture cards without tuners do exist, but these are not commonly used with MythTV. Sometimes people mistake video capture cards with video display cards which provide the output to the (tv)screen.

Types of cards

Analog framebuffer cards

These cards (also called frame grabbers and software encoders) are usually based on a chipset like the Bt848/878 or Conexant cx2388x, and decode broadcast NTSC, PAL, or Secam television. These cards deliver an unencrypted data stream to MythTV, which then encodes to MPEG-4 or RTjpeg using software encoders. Advantages of this type of card are:

Low cost

High flexibility -- you can choose your encoding method and employ filters prior to encoding

If you have the CPU power, MPEG-4 produces better quality with smaller file sizes than the MPEG-2 used with most hardware encoding cards

The main disadvantage of this type of card is the high CPU requirements. Depending on your encoding settings, you may need close to 1GHz of CPU speed to handle a single encoding stream, and more if you have multiple cards or want to play back while recording. MPEG-4 is particularly demanding; for systems with weaker CPUs, RTjpeg consumes less CPU time at the cost of larger file sizes and more digital video artifacts.

Analog Hardware-Encoding Cards

These cards, currently the Hauppauge PVR cards, the AVerMedia M179 and any other card which supports the V4L2 MPEG Encoder API, have a video processor onboard which compresses the tuned video signal into an RTjpeg, MPEG-2, or MPEG-4 program stream before sending it into the computer. The advantages of these cards are:

Greatly reduced load on the entire machine (with certain technical caveats). This is particularly important for machines with weak CPUs or when using multiple tuners in one system.

The reduced load means that your video stream is less likely to suffer from encoding "hiccups" if a process causes the system to become momentarily too busy to process the video.

Most hardware-encoding cards output an MPEG-2 stream, which can simplify backing up to DVD.

The main drawback of this type of card is that you're limited to the video format and encoding options supported by the manufacturer (usually MPEG-2). You can transcode to MPEG-4 after recording to save space, if desired, but this requires post-record processing and will degrade quality slightly.

Most cards of this type are designed to encode standard definition analog (NTSC, PAL, or SECAM) video signals. At least one product, though, the Hauppauge HD PVR, encodes analog HD output, as produced by cable or satellite TV boxes. Such a product is currently the only way to record HD content from providers that encrypt their digital data streams. (Some cable boxes have FireWire outputs, but cable operators often encrypt the IEEE-1394 output for some of the channels tuned by these boxes.)

Digital Hardware-MPEG cards

Digital broadcasting (for DVB and ATSC at least) is in the form of an MPEG-2 transport stream, so unlike analog capture cards, there is no need for any kind of onboard encoding engine, the required program stream is extracted and handed directly to the computer for viewing or saving. Some cards have a hardware Program ID filter (hardware pid) which means the card can extract the required program stream from the transport stream itself.

In either case, the computer power required to save a MPEG-2 transport stream (but not view it) is very small, being only what is required to shift data from the PCI/USB bus and save it to disk.

Confusingly, many useful tools for working with MPEG-2 transport streams have "dvb" in their names, even though they work just as well with MPEG-2 transport streams derived from "ATSC" broadcasts.

Some digital capture cards also support analog (NTSC or PAL) transmissions, usually via a frame grabber. If your digital capture card lacks such hardware and you want to record both digital and analog transmissions, you'll need to buy a separate analog capture card - either a frame grabber or a hardware-encoding card.

Some cable and satellite TV boxes include FireWire ports. You can use these ports, along with a FireWire port on your MythTV box, to record both analog and digital channels from the cable box. Essentially, the FireWire card and cable box function like a digital hardware MPEG card, although configuration details and capabilities differ. Depending on your cable operator, the channels tunable via the cable box may be the same as those that are tunable via a standard digital tuner card, or you may be able to record some or all of the cable system's encrypted channels, as well.

With the world moving towards digital broadcast standards, this type of card is likely to become dominant in the next few years.

Cards tested with MythTV

MythTV basicly supports all cards that are supported by the LinuxTV module. So you can choose any card thats registered as supported on the | LinuxTV site.

Because its practically impossible for us to test all these cards, we have added the cards that we have tested on MythTV below. Of course all the other "LinuxTV supported cards" should work as well.

If your card is not in this list and works with MythTV then we would appreciate it if you add it here so others can benefit from your experience. For specifications about a card you can go to | LinuxTV site or the site of the manufacturer.

Firewire Capture Cards

See the Firewire Cable Box Compatibility page for details of using a cable box with a FireWire port under MythTV. Support varies by cable operator and cable box, with the FireWire hardware and support software in the MythTV system also playing a role.

Capture Card Matrix

Please add your information to the heading "Cards tested with MythTV". This section is outdated and will also be moved there.

Because all the specifications in this matrix are also available and more up-to-date at | LinuxTV wiki (the module we use for MythTV), its unnecessary to update this matrix. Please add your findings and input to the group "Cards tested with MythTV" here on the page. Also for some of us a wiki table is not user friendly enough to work with.

DVB Driver from linux kernel 2.6.16, Works out of the box since Ubuntu 6.06 more info. The digital and analog tuner are recognized in one single card since Myth 0.20. Myth shows all of the digital and analog inputs including the S-video and RCA inputs on the card. Tested 43 HDTV channels with an indoor digital antenna

Has TV-out and if the option to encode CC in MPEG datastream is enabled, PVR-350 TV output can also pass it back to the television CC decoder. Not recommended for new purchases, as mpeg decoding does not support advanced myth functions (like fast-forwarding) and future versions of myth will use OpenGL, which will not work on this card. See Hauppauge_PVR-350 on this wiki!

This card is supported using the native V4l saa7146/stv0297 drivers. The 2.6.24 kernel drivers fixes the 1% signal strength bug. Note: The "HDTV version" of this card only includes an extra Windows HDTV codec so save the additional money and buy the "normal" version if you plan to use Linux.Note: Some (newer versions) of these cards do NOT work under Linux because of a different tuner. Mine doesn't. --Per Olofsson 15:09, 16 April 2008 (UTC)

Removed from matrix because I could not find any info at vendor websites (please re-add if you have info about these!):

Aver Desktop PVR

Cards that don't work

Here you find an overview of the cards not working with MythTV. In general the cards listed here as "not working" are the cards not supported by the LinuxTV module. So the fact that these doesn't work isn't a MythTV issue.

ATI All-in-Wonder cards

The ATI drivers provide a kernel module for basic V4L support which allows for capturing video from the device as it is playing. They do not, however, provide the tuner functions necessary for MythTV to select channels. Instead, they implement their channel tuning using the Xv extensions of X-Windows. A solution might be to patch the MythTV source code to recognize the ATI hardware and use Xv frequency changing to change the channel rather than solely relying on the V4L tuning functions. Then it would depend on whether the V4L support for capture is adequate enough in the ATI drivers for MythTV to work. It also might be possible to use an externally called Xv channel changing utility to change the channels.

The ATI All-in-Wonder card cannot (it is said elsewhere on the internet) send video across the PCI bus. It can only show video on the VGA output on the card. It is on this basis that neither the card nor drivers are appropriate for use with mythtv.

PVR-350 all functions work, but TV-Out isn't well suited for Myth, since it isn't accelerated and the MPEG decoder isn't well supported any longer.

Caveats

MPEG Tuner Card caveats are mostly that since these cards tend to be PCI busmasters, you may have to be careful how you put them in your machine (ie: which slots), where your VGA card is, and possibly what kind of motherboard you select, if you're planning on doing something silly like building a 10-tuner machine with 5 Hauppauge PVR-500's.